Earth working machine including scraper blade means

ABSTRACT

An earth working machine for towing at the rear of a tractor having an elongated scraper blade means extending transversely of the machine. Ground-traveling wheels are provided to the rear of the blade means, with hydraulically operated rams in the mounting for the wheels enabling adjustment of their elevation with respect to the blade means. The blade means has an internal pivot enabling extremities to be tilted to different relative adjusted positions about a horizontal axis extending from the front to the rear of the machine. Blade extensions are extendible from opposite ends of the blade means and the support wheels may also be shifted laterally outwardly. Different movements in the machine are remotely controlled by the operator of the tractor. The machine, through draft arm structures, is towed by the tractor, such structures connecting with the tractor frame in advance of the rear tractor wheels. A connection with the hydraulic lift arms of the tractor enables the machine to be raised from the ground.

i United States Patent 1 Layton 4] ARTH WORKING MACHINE INCLUDING SCRAPER BLADE MEANS [75] Inventor: Jack D. Layton, Salem, Oreg.

[73] Assignee: Layton Manufacturing Company,

Salem, Oreg.

[22] Filed: W181. 22, 1972 [21] Appl. No.: 237,187

[521 US. Cl 172/777, 172/413, 172/507,

1 1 172/666, 172/783 ,[51] Int. Cl E02f 3/12 [58] Field of Search 172/777, 786, 291,

[56 References Cited UNITEDSTATES PATENTS 2,051,283 8/1936 AUStiIl....' 172/413 3,034,238 5/1962 MCGC6 172/777 2,998,734 9/1961 Bunting 172/449 X 1,982,219 1 1/1934 MCAliStCI' 172/673 3,231,991 2/1966 Wandscheer et a1 172/782 X 3,512,589 5/1970 Ulrich 172/796 X 3,608,643 9/1971 FlOOd et al 172/507 X 1,676,548 7/1928 Gustafson 172/786 2,050,282 8/1936 [451 Dec. 4, 1973 r 2,765,721 10/1956 Smithm, 172/443 Primary Examiner-Stephen C. I Pellegrino 4ttorne y-M. H. Hartwell, Jr.

57 ABSTRACT An earthworking machine-for towing at the rear of a tractor having an elongated scraper blade means extending transversely of the machine. Ground-traveling wheels are provided to the rear of the b lade means, with hydraulically operated rams in the mounting for the wheels enabling adjustment of their elevation with respect to the blade means. The blade means has an internal pivot enabling extremities to be tilted to different relative adjusted positions about a horizontal axis extending from the front to the rear of the machine. Blade extensions are extendible from opposite ends of the blade means and the support wheels may also be shifted laterally outwardly. Different movements in the machine are remotely controlled by the operator of the tractor. The machine, through draft arm structures, is towed by the tractor, such structures connecting with the tractor frame in advance of the rear tractor wheels A connection with the hydraulic lift arms of the tractor enables the machine to be raised from the ground.

13 Claims, 9 Drawing Figures PATENTED DEC 4 ISIS SHEEI 10F 3 PMENIH DEC 4 1915 7 EARTH WORKING MACHINE INCLUDING SCRAPER BLADE MEANS This invention relates in general to an earth working machine featuring scraper blade means for leveling and otherwise contouring the terrain being worked.

The machine conceived by me has particular utility for paving contractors who, in the process of preparing a paved area, need to spread, level, and otherwise properly contour the ground area prior to the laying of the paving aggregate which surfaces the area.

A general object of the invention, therefore, is to provide a new and improved machine with scraper blade means for coupling with a tractor to be drawn by the tractor.

Another more specific object of the invention is to supporting devices, more specifically wheels, for partially supporting the rear of the blade means during scraping, with one being provided adjacent opposite extremities of the blade means. The wheels, through provide such a machine including ground-traveling tractor traveling over uneven terrain to be transmitted to the blade means to be reflected in changes in the position of such blade means.

Another object is to provide such a machine featuring means for attaching the same to the hydraulic lift arms of 'a tractor, enabling the machine when it is desired not to work the terrain to be lifted from the ground to be supported in an elevated position at the rear of the tractor.

A very important feature and object of the invention is the provision of a machine with scraper blade means, where the blade means includes a pair of blade sections disposed end-to-end, with pivot means interconnecting adjacent ends of the blade sections to enable relative adjustable pivotal movement about a horizontal axis extending transversely of the blade means. With such a construction, the scraper blade means may be adjusted to produce either a so-called crown, or valley, in the area being worked. The ground-traveling supporting devices or wheels which trail the blade means, through regulation of their position, control the working elevation of the blade means during such crowning or valleying.

As already described, a pair of ground-traveling supporting devices or wheels may be provided, withone to the rear and partially supporting each extremity of the scraper blade means. With the power-operatedmeans which mounts these devices permitting each deviceto be shifted in elevation relative to the scraper blade means independently of the other, it is possible to tilt the blade means, either when positioned to extend as a straight line, or with opposite blade sections in the blade means relatively angularly positioned as when producing a crown orvalley. This feature of the invention imparts considerable versatility to the machine, as

it permits a type of contouring in the terrain being worked heretofore difficult if not impossible toperform.

As a related object of the invention, the construction features blade extensions which may be extended out from one or both of opposite extremities of the blade means in the machine. This affords an opportunity to level and contour areas of different widths. With a blade extension extended out from one end of the blade means, it is possible to use one end in the leveling of an area which is located laterally of the area over which the tractor runs.

Various other objects and. advantages of the invention will become more fully apparent as the following description is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a sideelevation of an earth working ma 7 chine constructed as contemplated and showing such coupled to the rear of a tractor;

FIG. 2 is a rear elevation of the machine shown in FIG. 1 on a somewhat larger scale;

FIG. 3 is a plan view of the machine illustrated in FIG. 2;

FIG. 4 shows the machine as illustrated in on a larger scale;

FIG. 5 shows the blademeans of the machine'in one of its adjusted positions,

I FIG. 6 shows part of the structure used in connecting the machine to the lift arms of a tractor, and.

FIGS. 7, 8, and 9 are top, rear and side views, respectively, of a modified form of the invention.

Referring to FIG. 1, a tractor is shown at 3, having a frame 4, rear traction wheels 5, and front dirigible wheels 6. Shown supported 'at the front of the tractor is a bucket loader 7. Towed at the rear of the tractor is a scraping machine 8.

The scraping machine illustrated! comprises an elongated scraper blade means given the reference numeral tional with scrapers. Each blade section is disposed with the lower edge thereof inclining forwardly somewhat, so that on being drawn along the ground, the blade will dig into the ground to assume a proper working depth.

Blade sections 10a, 10b at their adjacent set of ends are pivotally interconnected by pivot means or connection 12. Such pivotal connection permits the blade sections to .be pivoted relative to each other, about a substantially horizontal and longitudinally extending axis, or an axis that extends transversely of the blade means as a whole. In FIG. 2, the blade sections are shown in solid outline with their bottom edges lying in a common plane, i.e., the sections are in an exactly aligned position. In dot-dashed outline in FIG. 2, the blade sections are shown pivoted relative to each other, whereby each inclines upwardly from pivot connection 12. The blade sections with this type of positioning are operable to produce a valley in the area being worked. The blade sections are also shown in dot-dash outline pivoted in FIG. 1, but

the opposite direction, whereby their bottom edges incline downwardly progressing from pivot connection 12. With this adjustment, the blade sections produce what is known as a crown in the area worked.

To produce relative adjustable movement in the blade sections, a fluid operated motor, such as the hydraulically operated ram shown at 14 is provided The ram is shown with its cylinder end journaled to a post joined to blade section a and its rod end journaled to a post joined to blade section 101;. By actuating the ram, the ram may be made to extend or contract, pro ducing relative shifting of the blade sections. With the ram having a given degree of extension and hydraulically locked, it serves to maintain the blade sections in a given relative adjusted position. With the supply and exhaust of fluid to the ram being controlled by a remotely located valve within easy reach of the tractor operator, the construction described permits close control of blade section positioning, with such being under the control of the tractor operator during the actual scraping operation.

At each end of blade means 10 a blade extension such as that shown at is provided. As best illustrated in FIGS. 3 and 4, such takes the form of a curved blade fittingdirectly against the inner side of a blade section as represented by blade section 10b. A vertically disposed edger plate 24 is secured to the end of the blade 20, which forms the outer extremity of the blade extension. Rectangular guide tube 26 secured to and extending along the back of blade section 10b slidably receives a guide rod 28 which has its end joined to the blade extension through edger plate 24. The construction described affords movement of the blade extension axially of the blade section 101) outwardly to one side of the machine, with such blade extension when extended forming an extension of blade section 10b.

To produce movement of a blade extension, a fluidoperated motor represented by hydraulic ram or motor 30 shown partially in FIG. 4 is included. Such is housed within the guide tube and has opposite extremities joined to the guide tube and guide rod, respectively. Again, by providing a valve for controlling the admission and exhaust of fluid to this ram located remotely and in a position to be manipulated by an operator of the tractor, it is possible to adjust the blade extension while performing the grading operation.

Providing support for the rear of the machine, whereby the blade means maintains its proper working depth, and also functioning to smooth out the travel of the blade means, are a pair of ground-traveling support devices shown at 32 and 34. Inthe particular embodiment illustrated, such comprise pneumatic wheels.

Considering the mounting of the wheels at the rear of the blade means, and with reference to wheel 34 (see FIG. 3), shown at 36 are brackets suitably fastened to the rear of the blade means through guide tube 26. A pin 38 journaled in these brackets has plates 40 joined to opposite ends, and these plates mount a tube 42 which generally parallels the axis of the blade means. The tube is swingable up and down, to effect a change in the elevation of the tube relative to the blade section in front of it.

Telescopically received within tube 42 is a cylindrical bar 44. Wheel 34 is journaled on the end of the bar. The construction described constitutes an adjustable mounting for the wheel, whereby it is movable outwardly, in a direction substantially paralleling the axis of the scraper blade means. To secure the bar and tube' in a given relative position, a fastener 46 is provided, which fits through an accommodating bore in the tube and one of multiple bores 45 provided in the bar 44.-

The wheels are located outwardly toward opposite ends of the blade means from pivot connection 12, and perform their stabilizing and depth positioning function with the blade sections exactly aligned, or adjusted to produce crowns or valleys.

With lowering of a wheel with respect to the blade section in front of it, the blade section works at a shallower depth, and with raising of the wheel the section works at a deeper depth. To position a wheel, a fluidoperated motor 50 is included for each wheel in the form of a fluid-operated ram extending between a plate 40 and the blade means. The supply and exhaust of fluid to a ram is controlled by a remotely located control valve as will be described, which enables the ram to be extended or contracted with the blade means performing a scraping operation. With hydraulical locking of the ram, the wheel which is controlled by it remains in a fixed adjusted position.

Each of the wheels is adjustable independently of the other. This is important, as it enables such positioning as a side tilt to be introduced to the blade means as a whole. This tilt can be toward either side of the machine. It is also possible to provide with this organization a number of different profiles unobtainable with ordinary machines. For example, the blade means may be adjusted to produce a valley, and the two wheels described adjusted to produce a different working depth in one side of the blade means than the other. With this condition of the parts, a relatively level path may be scraped by the blade section working at the greater depth, and an inclined path scraped by the blade section working at the lesser depth. Such positioning of the blade means is shown in a somewhat simplified drawing in FIG. 5.

Projecting upwardly and forwardly from the scraper blade means are a pair of laterally spaced stanchions 52, 54. These are used in the mounting of the draft means which connects the machine to a drawing tractor. They are also utilized in the mounting of scarifiers 56, 58.

Considering by way of example, scarifier 56, such includes scarifier teeth mounted on a bar 62 journaled at one end at 63 in a bracket 64. The opposite end of a bar 62 is journaled in stanchion 52. The scarifier in the drawings is shown in a stored position. The mounting described enables the teeth to be swung forwardly to move them into ground contact.

Scarifier 56 is moved under power by actuation of ram 65 (see FIG. 3) having its rod end connected to shaft 62 through arm 66. A remote control valve controls actuation of ram 65.

Considering now the draft means provided for connecting the machine to a tractor, and with particular reference vto FIGS. 1, 3 and 4, shown straddling the tractor frame and projecting forwardly from the machine are a pair of draft arm structures given the refer ence numerals and 72, respectively. The two draft 'arm structures are similar, and only one will be described in detail.

Considering structure 70, such includes a draft bar 74 journaled at 76 on stanchion 52. Below this draft bar and journaled on the stanchion at 78 is a second draft bar 80. The forward ends of draft bars 74, 80 converge and join (see FIG. 1) adjacent where the arm structure is connected to the tractor, at 82. This connection is a pivot connection and is disposed forwardly of the rotation axis of the rear traction wheels.

Because pivot connection 82 is between the front and rear wheels of the tractor, the connection travels in a more level path than do the wheels at the ends of the tractor, on the tractor moving over uneven ground. This, and the fact that the draft arm structure has considerable length, where such extends from pivot connection 82 to the wheels 32, 34, contribute to stabilizing .the depth at which the scraper blade means is pulled over the terrain.

Draft bar 80 (see FIG. 4) includes relatively extensible sections 80a, 80b. Means 84 may be loosened, to permit adjustable extensible movement of these two sections, and with tightening of means 84, the sectionsare rigidly joined in their adjusted position. Varying the length of bar 80 has the effect of varying the attitude at which the blade means is carried.

The tractor illustrated has the usual hydraulic lift arms indicated in FIG. 6 at 86. Shown at 90 are tractor draw bars. Means is provided located between draft arm structures 70, 72 for coupling the machine to the tractor lift arms, whereby the same may be lifted from the ground to place it in an inoperative position.

More specifically, spanning the hydraulic lift arm 86 and the draw bar 90 on each side of the tractor is a link structure 94. Each link structure includes a clevice number 98 journaled at 100 to the draw bar, and a rod portion 102 at the upper extremity thereof loosely passmaneuvered using the bucket. Upon completion of the I ing through a sleeve 104 carried at the end of the lift arm. Stops 106, 108 are joined to rod portion 102 on either side of the sleeve. The construction provides a lost motion connection, whereby limited up and down movement of the link structure is permitted without -movement being imparted to the hydraulic lift arm.

Extending between rearward extremities of the draw bars is a shaft 110. The outer extremities of the 'shaft are linked through plates such as the one shown at 112 to the draft arm structures on either side of the machine. I

To raise the machine and lift it from the ground, the hydraulic lift arms are raised. On sleeves 104 in the lift arms striking stops 106, upward movement is imparted to the draft arm structures 70, 72. Lowering of the ma chine is accomplished by lowering of the arms, with the draft arm structures in the machine then falling by gravity toward the ground.

Shown at 120 is a valve assembly with multiple valves 122 controlling flow in various hydraulic lines that supply the motors or rams producing adjustments in the machine. Specific hydraulic hose connections have not been illustrated in order to simplify the drawings. It should be understood however, that each of the rams controlling wheel height is provided with a separate control valve, as well as each of the rams controlling blade extension, each of the rams controlling the posi* tion of a scarifier, and the ram which is actuated pivotally to adjust the blade sections with respect to each other. The valve assembly is mounted on the tractor directly behind operator seat 123, and flexible hoses on lines such as those shown at 125 connect the valves with rams in the scraping machine.

It is contemplated that the machine described frequently will be installed on a tractor where such may have a bucket or loader such as the one shown at 7 mounted at the front end of the tractor. With this combination, a highly versatile type of unit is provided, which enables a contractor very quickly to grade an area to prepare the same for paving. During use of the bucket, in moving earth and gravel when performing filling and the like, the earth working or scraping machine with blade means may be raised and the tractor filling, the bucket may be-raised and the scraping machine lowered to the ground and placed into operation.-

Referring now to FIGS. "7, 8 and 9, here a modified form of applicants invention is disclosed. As in applicants first described modification of the invention the machine in these figures includes scraper blademeans 10 having a pair of blade sections 10a and 10b disposed end to end pivotally interconnected by pivot means 12.

In the apparatus of these figures, ground traveling support devices 130,132 are shown for supporting the rear of the apparatus for movement over the ground. Each of these includes a pair of wheels arranged in tandem whereby a level ride is'obtained in the wheel device.

The two wheel devices are similar in construction. Describing wheeldevice 132 such includes a caster wheel 134 and a caster wheel 136, each swiveled as at 138, on a wheel mounting 140. The wheel mounting in turn is joumaled at 142 on an arm 144.

Secured to the forward end of arm 144 is a rod 146 of rectangular cross section which extends generally transversely of the longitudinal axis of the tractor which tows the apparatus. The rod is slidably received within guide portions 148 of bracket structure 150.

Also mounted on bracket structure 150 is the cylinder portion of a ram 152 which has its rod end 154 connected to arm 144. With the construction described, on extension of the ram 52 the arm and wheel mounting together with the caster wheels are shifted laterally outwardly on the device. Conversely with contraction of the ram, the parts are moved laterally inwardly. The ram ordinarily is remotely controlled by valve means within the reach of the tractor operator. This gives the operator the capability of making adjustments in the lateral positioning of the wheel supports from the trac tor seat and while performing a grading operation.

Bracket structure 150 is pivotally mounted at 156 to guide tube 26 forming part of the blade means. A hydraulic ram 158 interposed between the bracket structure and stanchion 160 is actuatablle to raise and lower the wheel device. Thus, ram 158 may be likened to ram 50 discussed in connection with the first modification of the invention described herein.

In performing a grading operation, it should be obvi ous that during a pass with the tractor, considerably varied types of contours may be produced. Further, it is possible to level and grade areas hard to reach with conventional equipment. For instance, it is possible to grade a stretch to have partially a substantially level exspirit of the invention.

It is claimed and desired to secure by Letters Patent: 1. An earth working machine adapted to be connected to a tractor to be towed by the tractor comprising elongated scraper blade means extending across the machine between the sides of the machine, said scraper blade means including a pair of blade sections disposed end to end and pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative pivotal movement about a substantially horizontal axis extending transversely of the blade means, at least a pair of ground-traveling supporting devices positioned to the rear of said scraper blade means, with one disposed adjacent one side and the other adjacent the other side of said machine,

power-operated means for each supporting device mounting the device on said blade means and on being actuated operable to change the relative elevation of the supporting device with respect to said blade means, the power-operated means for each supporting device being actuatable independently of the other, 7

draft means extending forwardly of the blade means for connecting the machine to the tractor, and

a remote control for said power-operated means flexibly connected thereto, adapted to be positioned adjacent the operator of the tractor whereby the same may be manipulated by such operator during towing of the machine.

2. The earth working machine'of claim 1, wherein said scraper blade means includes at least one end thereof a blade extension extendible outwardly along the axis of the scraper blade means to one side of the machine, and wherein the ground-traveling device which is at said one side of the machine is adjustably mounted for movement outwardly in a direction substantially paralleling said axis.

3. The earth working machine of claim I, wherein power-operated means is provided between the blade sections to permit relative adjustable pivotal movement in the blade sections under power, each of said groundtraveling support devices comprises a wheel, and said power-operated means for mounting a device comprises a bar having the wheel journaled on an end thereof, a sleeve mounting said bar extending along the axis of said scraper blade means with the bar adjustably extensible in said sleeve, means disposed to the rear of said blade means mounting said sleeve for vertical movement relative to the blade means, and a hydraulic motor positioned between the sleeve and blade means for adjusting the position of said sleeve under power.

4. The earth working machine of claim 1, wherein said scraper blade means further comprises poweroperated means provided between the blade sections to permit relative adjustable pivotal movement in the blade sections under power.

5. The earth working machine of claim 1, which further includes draft means for towing the machine, said draft means comprising a pair of draft arm structures extending forwardly from the scraper blade means with coupling means at the forward extremities of such structures for making a draft connection with a tractor, and means disposed intermediate said draft arm structures for connecting the machine to the lift arm structure of a tractor, each draft arm structure comprising a pair of draft bars joined at their forward ends, a forwardly projecting stanchion for each draft arm structure connected to and extending above the scraper blade means, the draft bars in a draft arm structure being connected at their rear ends to a stanchion at vertically spaced points.

6. In combination with a tractor having a frame, traction wheels at the rear end thereof, and poweroperated hitch arms movable up and down under power disposed between said wheels at the rear of the tractor,

an elongated scraper blade means disposed to the rear of said tractor wheels,

a pair of draft arm structures straddling the tractor frame and journaled to the tractor frame at a point disposed forwardly of said traction wheels, said arm structures being connected to the scraper blade means adjacent opposite ends,

means disposed between said draft arm structures joining the scraper blade means and the tractor hitch arms to enable raising and lowering of the blade means with raising and lowering of said arms,

at least a pair of scraper blade ground-traveling supports disposed to the rear of said scraper blade means, and

power-operated means for each scraper blade support mounting the support on said blade and on being actuated operable to change the relative elevation of the support with respect to said scraper blade means.

7. The combination of claim 6, wherein a pair of forwardly projecting stanchions are joined to the scraper blade means, one for each draft arm structure, and each draft arm structure comprises a pair of draft bars joined at their forward ends and connected at vertically spaced points at their rear ends to a stanchion.

8. The combination of claim 7, wherein at least one draft arm bar in a draft arm structure is adjustably extensible.

9. The combination of claim 6, wherein said Scraper blade means comprises a pair of blade sections disposed end-to-end with pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative pivotal movement about an axis extending normal to the blade sections, and said scraper blade ground-traveling supports are disposed with one located toward one end of the blade means from said pivot means and the other located toward the other end of the blade means from said pivot means.

10. The combination of claim 6, wherein said scraper blade means includes at atleast one end a blade extension extensible outwardly along the axis of the scraper blade means, and wherein a scraper blade groundtraveling support located to the rear of said end of said blade means is adjustably mounted for movement outwardly in a direction substantially paralleling the axis of the blade means.

11. An earth working machine adapted to be towed behind a vehicle comprising an elongated scraperblade means extending across the machine between the sides of the machine, said scraper blade means comprising a pair of blade sections disposed end-to-end and pivot means pivotally interconnecting adjacent ends of the blade sectionsto enable relative pivotal movement about a substantially horizontal axis extending transversely of the blade sections,

sections for producing relative adjustable pivotal movement under power, i

at least a pair of ground-traveling supportdevices disposed to the rear of the scraper blade means with one located toward one end of the blade means from said pivot means and one located toward the opposite end of the blade means from said pivot means,

and power-operated means mounting each of said ground-traveling support devices on the blade means operable to produce on actuation thereof a change in the relative elevation of the groundtraveling support device with respect to said blade means, the power-operated means for the respective ground-traveling support devices being actuatable independently of each other.

12. The earth working machine of claim 11, wherein the scraper blade means includes blade extensions extendible outwardly along the axis of the scraper blade means from opposite ends of the scraper blade means,

and wherein the ground-traveling support devices are scraper blade means comprising a pair of blade sec- I tions disposed end-to-end and pivot means pivot ally interconnecting adjacent ends of the blade sections to enable relative adjustable pivotal move ment about a substantially horizontal axis extending transversely of the blade means, means interposed between the blade sections for setting them at different relatively adjusted pivoted positions,

at least a pair of ground-traveling support devices disposed to the rear of the scraper blade means with one located toward one end of the blade means from said pivot means and one located toward the opposite end of the blade means from said pivot means, power-operated means mounting each of said ground-traveling support devices on the blade means operable to produce on actuation thereof a change in' the relative elevation of the groundtraveling support device with respect to said blade means,

the scraper blade means further including at at least oneend'thereof, a blade extension ex'tehdible outwardly along the axis of the scraper blade means to one side of the machine, the ground-traveling device which is at said one side of the machine being adjustably mounted for movement outwardly in a direction substantially paralleling said axis. 

1. An earth working machine adapted to be connected to a tractor to be towed by the tractor comprising elongated scraper blade means extending across the machine between the sides of the machine, said scraper blade means including a pair of blade sections disposed end to end and pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative pivotal movement about a substantially horizontal axis extending transversely of the blade means, at least a pair of ground-traveling supporting devices positioned to the rear of said scraper blade means, with one disposed adjacent one side and the other adjacent the other side of said machine, power-operated means for each supporting device mounting the device on said blade means and on being actuated operable to change the relative elevation of the supporting device with respect to said blade means, the power-operated means for each supporting device being actuatable independently of the other, draft means extending forwardly of the blade means for connecting the machine to the tractor, and a remote control for said power-operated means flexibly connected thereto, adapted to be positioned adjacent the operator of the tractor whereby the same may be manipulated by such operator during towing of the machine.
 2. The earth working machine of claim 1, wherein said scraper blade means includes at least one end thereof a blade extension extendible outwardly along the axis of the scraper blade means to one side of the machine, and wherein the ground-traveling device which is at said one side of the machine is adjustably mounted for movement outwardly in a direction substantially paralleling said axis.
 3. The earth working machine of claim 1, wherein power-operated means is provided between the blade sections to permit relative adjustable pivotal movement in the blade sections under power, each of said ground-traveling support devices comprises a wheel, and said power-operated means for mounting a device comprises a bar having the wheel journaled on an end thereof, a sleeve mounting said bar extending along the axis of said scraper blade means with the bar adjustably extensible in said sleeve, means disposed to the rear of said blade means mounting said sleeve for vertical movement relative to the blade means, and a hydraulic motor positioned between the sleeve and blade means for adjusting the position of said sleeve under power.
 4. The earth working machine of claim 1, wherein said scraper blade means further comprises power-operated means provided between the blade sections to permit relative adjustable pivotal movement in the blade sections under power.
 5. The earth working machine of claim 1, which further includes draft means for towing the machine, said draft means comprising a pair of draft arm structures extending forwardly from the scraper blade means with coupling means at the forward extremities of such structures for making a draft connection with a tractor, and means disposed intermediate said draft arm structures for connecting the machine to the lift arm structure of a tractor, each draft arm structure comprising a pair of draft bars joined at their forward ends, a forwardly projecting stanchion for each draft arm structure connected to and extending above the scraper blade means, the draft bars in a draft arm structure being connected at their rear ends to a stanchion at vertically spaced points.
 6. In combination with a tractor having a frame, traction wheels at the rear end thereof, and power-operated hitch arms movable up and down under power disposed between said wheels at the rear of the tractor, an elongated scraper blade means disposed to the rear of said tractor wheels, a pair of draft arm structures straddling the tractor frame and journaled to the tractor frame at a point disposed forwardly of said traction wheels, said arm structures being connected to the scraper blade means adjacent opposite ends, means disposed between said draft arm structures joining the scraper blade means and the tractor hitch arms to enable raising and lowering of the blade means with raising and lowering of said arms, at least a pair of scraper blade ground-traveling supports disposed to the rear of said scraper blade means, and power-operated means for each scraper blade support mounting the support on said blade and on being actuated operable to change the relative elevation of the support with respect to said scraper blade means.
 7. The combination of claim 6, wherein a pair of forwardly projecting stanchions are joined to the scraper blade means, one for each draft arm structure, and each draft arm structure comprises a pair of draft bars joined at their forward ends and connected at vertically spaced points at their rear ends to a stanchion.
 8. The combination of claim 7, wherein at least one draft arm bar in a draft arm structure is adjustably extensible.
 9. The combination of claim 6, wherein said scraper blade means comprises a pair of blade sections disposed end-to-end with pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative pivotal movement about an axis extending normal to the blade sections, and said scraper blade ground-traveling supports are disposed with one located toward one end of the blade means from said pivot means and the other located toward the other end of the blade means from said pivot means.
 10. The combination of claim 6, wherein said scraper blade means includes at at least one end a blade extension extensible outwardly along the axis of the scraper blade means, and wherein a scraper blade ground-traveling support located to the rear of said end of said blade means is adjustably mounted for movement outwardly in a direction substantially paralleling the axis of the blade means.
 11. An earth working machine adapted to be towed behind a vehicle comprising an elongated scraper blade means extending across the machine between the sides of the machine, said scraper blade means comprising a pair of blade sections disposed end-to-end and pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative pivotal movement about a substantially horizontal axis extending transversely of the blade sections, power-operated means interposed between the blade sections for producing relative adjustable pivotal movement under power, at least a pair of ground-traveling support devices disposed to the rear of the scraper blade means with one located toward one end of the blade means from said pivot means and one located toward the opposite end of the blade means from said pivot means, and power-operated means mounting each of said ground-traveling support devices on the blade means operable to produce on actuation thereof a change in the relative elevation of the ground-traveling support device with respect to said blade means, the power-operated means for the respective ground-traveling support devices being actuatable independently of each other.
 12. The earth working machine of claim 11, wherein the scraper blade means includes blade extensions extendible outwardly along the axis of the scraper blade means from opposite ends of the scraper blade means, and wherein the ground-traveling support devices are adjustably mounted for movement outwardly in a direction substantially paralleling said axis.
 13. An earth working machine adapted to be towed behind a vehicle comprising an elongated scraper blade means extending across the machine between the sides of the machine, said scraper blade means comprising a pair of blade sections disposed end-to-end and pivot means pivotally interconnecting adjacent ends of the blade sections to enable relative adjustable pivotal movement about a substantially horizontal axis extending transversely of the blade means, means interposed between the blade sections for setting them at different relatively adjusted pivoted positions, at least a pair of ground-traveling support devices disposed to the rear of the scraper blade means with one located toward one end of the blade means from said pivot means and one located toward the opposite end of the blade means from said pivot means, power-operated means mounting each of said ground-traveling support devices on the blade means operable to produce on actuation thereof a change in the relative elevation of the ground-traveling support device with respect to said blade means, the scraper blade means further including at at least one end thereof, a blade extension extendible outwardly along the axis of the scraper blade means to one side of the machine, the ground-traveling device which is at said one side of the machine being adjustably mounted for movement outwardly in a direction substantially paralleling said axis. 